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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT>     * contributor license agreements.  See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT>     * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT>     * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT>     * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT>     * the License.  You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT>     * See the License for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT>     * limitations under the License.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    package org.apache.commons.math3.geometry.euclidean.twod;<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    import org.apache.commons.math3.util.FastMath;<a name="line.19"></a>
<FONT color="green">020</FONT>    <a name="line.20"></a>
<FONT color="green">021</FONT>    /** Simple container for a two-points segment.<a name="line.21"></a>
<FONT color="green">022</FONT>     * @version $Id: Segment.java 1422195 2012-12-15 06:45:18Z psteitz $<a name="line.22"></a>
<FONT color="green">023</FONT>     * @since 3.0<a name="line.23"></a>
<FONT color="green">024</FONT>     */<a name="line.24"></a>
<FONT color="green">025</FONT>    public class Segment {<a name="line.25"></a>
<FONT color="green">026</FONT>    <a name="line.26"></a>
<FONT color="green">027</FONT>        /** Start point of the segment. */<a name="line.27"></a>
<FONT color="green">028</FONT>        private final Vector2D start;<a name="line.28"></a>
<FONT color="green">029</FONT>    <a name="line.29"></a>
<FONT color="green">030</FONT>        /** End point of the segments. */<a name="line.30"></a>
<FONT color="green">031</FONT>        private final Vector2D end;<a name="line.31"></a>
<FONT color="green">032</FONT>    <a name="line.32"></a>
<FONT color="green">033</FONT>        /** Line containing the segment. */<a name="line.33"></a>
<FONT color="green">034</FONT>        private final Line     line;<a name="line.34"></a>
<FONT color="green">035</FONT>    <a name="line.35"></a>
<FONT color="green">036</FONT>        /** Build a segment.<a name="line.36"></a>
<FONT color="green">037</FONT>         * @param start start point of the segment<a name="line.37"></a>
<FONT color="green">038</FONT>         * @param end end point of the segment<a name="line.38"></a>
<FONT color="green">039</FONT>         * @param line line containing the segment<a name="line.39"></a>
<FONT color="green">040</FONT>         */<a name="line.40"></a>
<FONT color="green">041</FONT>        public Segment(final Vector2D start, final Vector2D end, final Line line) {<a name="line.41"></a>
<FONT color="green">042</FONT>            this.start  = start;<a name="line.42"></a>
<FONT color="green">043</FONT>            this.end    = end;<a name="line.43"></a>
<FONT color="green">044</FONT>            this.line   = line;<a name="line.44"></a>
<FONT color="green">045</FONT>        }<a name="line.45"></a>
<FONT color="green">046</FONT>    <a name="line.46"></a>
<FONT color="green">047</FONT>        /** Get the start point of the segment.<a name="line.47"></a>
<FONT color="green">048</FONT>         * @return start point of the segment<a name="line.48"></a>
<FONT color="green">049</FONT>         */<a name="line.49"></a>
<FONT color="green">050</FONT>        public Vector2D getStart() {<a name="line.50"></a>
<FONT color="green">051</FONT>            return start;<a name="line.51"></a>
<FONT color="green">052</FONT>        }<a name="line.52"></a>
<FONT color="green">053</FONT>    <a name="line.53"></a>
<FONT color="green">054</FONT>        /** Get the end point of the segment.<a name="line.54"></a>
<FONT color="green">055</FONT>         * @return end point of the segment<a name="line.55"></a>
<FONT color="green">056</FONT>         */<a name="line.56"></a>
<FONT color="green">057</FONT>        public Vector2D getEnd() {<a name="line.57"></a>
<FONT color="green">058</FONT>            return end;<a name="line.58"></a>
<FONT color="green">059</FONT>        }<a name="line.59"></a>
<FONT color="green">060</FONT>    <a name="line.60"></a>
<FONT color="green">061</FONT>        /** Get the line containing the segment.<a name="line.61"></a>
<FONT color="green">062</FONT>         * @return line containing the segment<a name="line.62"></a>
<FONT color="green">063</FONT>         */<a name="line.63"></a>
<FONT color="green">064</FONT>        public Line getLine() {<a name="line.64"></a>
<FONT color="green">065</FONT>            return line;<a name="line.65"></a>
<FONT color="green">066</FONT>        }<a name="line.66"></a>
<FONT color="green">067</FONT>    <a name="line.67"></a>
<FONT color="green">068</FONT>        /** Calculates the shortest distance from a point to this line segment.<a name="line.68"></a>
<FONT color="green">069</FONT>         * &lt;p&gt;<a name="line.69"></a>
<FONT color="green">070</FONT>         * If the perpendicular extension from the point to the line does not<a name="line.70"></a>
<FONT color="green">071</FONT>         * cross in the bounds of the line segment, the shortest distance to<a name="line.71"></a>
<FONT color="green">072</FONT>         * the two end points will be returned.<a name="line.72"></a>
<FONT color="green">073</FONT>         * &lt;/p&gt;<a name="line.73"></a>
<FONT color="green">074</FONT>         *<a name="line.74"></a>
<FONT color="green">075</FONT>         * Algorithm adapted from:<a name="line.75"></a>
<FONT color="green">076</FONT>         * &lt;a href="http://www.codeguru.com/forum/printthread.php?s=cc8cf0596231f9a7dba4da6e77c29db3&amp;t=194400&amp;pp=15&amp;page=1"&gt;<a name="line.76"></a>
<FONT color="green">077</FONT>         * Thread @ Codeguru&lt;/a&gt;<a name="line.77"></a>
<FONT color="green">078</FONT>         *<a name="line.78"></a>
<FONT color="green">079</FONT>         * @param p to check<a name="line.79"></a>
<FONT color="green">080</FONT>         * @return distance between the instance and the point<a name="line.80"></a>
<FONT color="green">081</FONT>         * @since 3.1<a name="line.81"></a>
<FONT color="green">082</FONT>         */<a name="line.82"></a>
<FONT color="green">083</FONT>        public double distance(final Vector2D p) {<a name="line.83"></a>
<FONT color="green">084</FONT>            final double deltaX = end.getX() - start.getX();<a name="line.84"></a>
<FONT color="green">085</FONT>            final double deltaY = end.getY() - start.getY();<a name="line.85"></a>
<FONT color="green">086</FONT>    <a name="line.86"></a>
<FONT color="green">087</FONT>            final double r = ((p.getX() - start.getX()) * deltaX + (p.getY() - start.getY()) * deltaY) /<a name="line.87"></a>
<FONT color="green">088</FONT>                             (deltaX * deltaX + deltaY * deltaY);<a name="line.88"></a>
<FONT color="green">089</FONT>    <a name="line.89"></a>
<FONT color="green">090</FONT>            // r == 0 =&gt; P = startPt<a name="line.90"></a>
<FONT color="green">091</FONT>            // r == 1 =&gt; P = endPt<a name="line.91"></a>
<FONT color="green">092</FONT>            // r &lt; 0 =&gt; P is on the backward extension of the segment<a name="line.92"></a>
<FONT color="green">093</FONT>            // r &gt; 1 =&gt; P is on the forward extension of the segment<a name="line.93"></a>
<FONT color="green">094</FONT>            // 0 &lt; r &lt; 1 =&gt; P is on the segment<a name="line.94"></a>
<FONT color="green">095</FONT>    <a name="line.95"></a>
<FONT color="green">096</FONT>            // if point isn't on the line segment, just return the shortest distance to the end points<a name="line.96"></a>
<FONT color="green">097</FONT>            if (r &lt; 0 || r &gt; 1) {<a name="line.97"></a>
<FONT color="green">098</FONT>                final double dist1 = getStart().distance(p);<a name="line.98"></a>
<FONT color="green">099</FONT>                final double dist2 = getEnd().distance(p);<a name="line.99"></a>
<FONT color="green">100</FONT>    <a name="line.100"></a>
<FONT color="green">101</FONT>                return FastMath.min(dist1, dist2);<a name="line.101"></a>
<FONT color="green">102</FONT>            }<a name="line.102"></a>
<FONT color="green">103</FONT>            else {<a name="line.103"></a>
<FONT color="green">104</FONT>                // find point on line and see if it is in the line segment<a name="line.104"></a>
<FONT color="green">105</FONT>                final double px = start.getX() + r * deltaX;<a name="line.105"></a>
<FONT color="green">106</FONT>                final double py = start.getY() + r * deltaY;<a name="line.106"></a>
<FONT color="green">107</FONT>    <a name="line.107"></a>
<FONT color="green">108</FONT>                final Vector2D interPt = new Vector2D(px, py);<a name="line.108"></a>
<FONT color="green">109</FONT>                return interPt.distance(p);<a name="line.109"></a>
<FONT color="green">110</FONT>            }<a name="line.110"></a>
<FONT color="green">111</FONT>        }<a name="line.111"></a>
<FONT color="green">112</FONT>    }<a name="line.112"></a>




























































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